Create "Open In Gitpod (JetBrains)" button

[loujaybee]

Create an "Open In JetBrains" button, which allows users to force open a project within JetBrains. This UX would be useful to support our work on the JetBrains integration. In terms of solution, I believe this can be done via URL parameters.

Related to:

• [server] add editor prefix to choose custom IDE #9467

[akosyakov]

I reopen it, since i thought to reuse new referrer prefix for that, but it is not really great, since it will disturb our data about local clients. I will add a dedicated prefix for that instead.